tarinai/js/assets.js

"use strict";
const images = new Map();
const imageBoundsCache = new WeakMap();
const imageMetrics = new Map();

const scaledSpriteCache = new Map();
const stainOverlayCache = new Map();

function trimCanvasCache(cache, limit = 420) {
  while (cache.size > limit) {
    const first = cache.keys().next().value;
    if (first === undefined) break;
    cache.delete(first);
  }
}

function quantizedCanvasSize(v, step = 16) {
  return Math.max(1, Math.round(v / step) * step);
}

const SPRITE_CACHE_SCALE = 2.0;

function getCachedSpriteCanvas(id, img, w, h) {
  if (!img || !w || !h) return img;
  const qw = quantizedCanvasSize(w, 16);
  const qh = quantizedCanvasSize(h, 16);
  const key = `${id}:${qw}x${qh}`;
  let canvas = scaledSpriteCache.get(key);
  if (canvas) return canvas;
  canvas = document.createElement("canvas");
  canvas.width = qw;
  canvas.height = qh;
  const c = canvas.getContext("2d");
  c.imageSmoothingEnabled = true;
  if ("imageSmoothingQuality" in c) c.imageSmoothingQuality = "high";
  c.clearRect(0, 0, qw, qh);
  c.drawImage(img, 0, 0, qw, qh);
  scaledSpriteCache.set(key, canvas);
  trimCanvasCache(scaledSpriteCache, 520);
  return canvas;
}

function getCachedStainOverlayCanvas(id, img, w, h, stain = 0, seed = 0.5) {
  if (!img || stain <= 0.01 || !w || !h) return null;
  const qw = quantizedCanvasSize(w, 16);
  const qh = quantizedCanvasSize(h, 16);
  const bucket = Math.max(1, Math.min(8, Math.ceil(stain * 8)));
  const seedBucket = Math.round((seed || 0) * 16);
  const key = `${id}:${qw}x${qh}:s${bucket}:r${seedBucket}`;
  let canvas = stainOverlayCache.get(key);
  if (canvas) return canvas;
  canvas = document.createElement("canvas");
  canvas.width = qw;
  canvas.height = qh;
  const c = canvas.getContext("2d");
  c.imageSmoothingEnabled = true;
  if ("imageSmoothingQuality" in c) c.imageSmoothingQuality = "high";
  c.clearRect(0, 0, qw, qh);
  c.drawImage(img, 0, 0, qw, qh);
  c.globalCompositeOperation = "source-in";
  c.globalAlpha = 0.34 + bucket * 0.075;
  c.fillStyle = "rgba(28, 92, 22, 0.96)";
  const s = (seedBucket % 16) / 16;
  const spots = [
    [0.40 + s * 0.035, 0.82, 0.14, 0.040, -0.10],
    [0.59 - s * 0.030, 0.87, 0.15, 0.044, 0.12],
    [0.50, 0.91, 0.20, 0.036, 0.02],
    [0.48 + s * 0.020, 0.78, 0.10, 0.030, -0.18],
  ];
  for (const [sx, sy, rw, rh, rot] of spots) {
    c.beginPath();
    c.ellipse(sx * qw, sy * qh, rw * qw, rh * qh, rot, 0, Math.PI * 2);
    c.fill();
  }
  c.globalAlpha = 1;
  c.globalCompositeOperation = "source-over";
  stainOverlayCache.set(key, canvas);
  trimCanvasCache(stainOverlayCache, 360);
  return canvas;
}

function loadImages() {
  const assets = [...SPRITES, ...DECOR_ASSETS];
  let loaded = 0;
  return new Promise((resolve) => {
    for (const s of assets) {
      const img = new Image();
      img.onload = img.onerror = () => {
        const w = img.naturalWidth || img.width || ALPHA_BOUNDS[s.id]?.imageW || 512;
        const h = img.naturalHeight || img.height || ALPHA_BOUNDS[s.id]?.imageH || 512;
        const bounds = ALPHA_BOUNDS[s.id] || { x: 0, y: 0, w, h, imageW: w, imageH: h };
        imageMetrics.set(s.id, {
          w,
          h,
          ratio: h / Math.max(w, 1),
          visibleBottomRatio: (bounds.y + bounds.h) / Math.max(bounds.imageH, 1),
        });
        loaded += 1;
        if (loaded === assets.length) resolve();
      };
      img.alphaBounds = ALPHA_BOUNDS[s.id] || null;
      img.src = s.path;
      images.set(s.id, img);
    }
  });
}

function imageAlphaBounds(img) {
  if (!img) return null;
  if (img.alphaBounds) return img.alphaBounds;
  if (imageBoundsCache.has(img)) return imageBoundsCache.get(img);

  const w = img.naturalWidth || img.width || 0;
  const h = img.naturalHeight || img.height || 0;
  if (!w || !h) return null;
  const bounds = { x: 0, y: 0, w, h, imageW: w, imageH: h };
  imageBoundsCache.set(img, bounds);
  return bounds;
}

function getImageMetrics(idOrImg) {
  if (typeof idOrImg === "string") return imageMetrics.get(idOrImg) || null;
  if (!idOrImg) return null;
  for (const [id, img] of images) {
    if (img === idOrImg) return imageMetrics.get(id) || null;
  }
  const w = idOrImg.naturalWidth || idOrImg.width || 0;
  const h = idOrImg.naturalHeight || idOrImg.height || 0;
  return w && h ? { w, h, ratio: h / w, visibleBottomRatio: 1 } : null;
}


window.TarinaiAssets = { images, imageBoundsCache, imageMetrics, scaledSpriteCache, stainOverlayCache, loadImages, imageAlphaBounds, getImageMetrics, getCachedSpriteCanvas, getCachedStainOverlayCanvas };